diff --git a/.idea/libraries/espresso_core_2_2_2.xml b/.idea/libraries/espresso_core_2_2_2.xml
deleted file mode 100644
index 1fe68a26..00000000
--- a/.idea/libraries/espresso_core_2_2_2.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<component name="libraryTable">
-  <library name="espresso-core-2.2.2">
-    <CLASSES>
-      <root url="file://$USER_HOME$/.android/build-cache/d505abdc89cc7d1b938ec3f95e87d4323360fa14/output/res" />
-      <root url="jar://$USER_HOME$/.android/build-cache/d505abdc89cc7d1b938ec3f95e87d4323360fa14/output/jars/classes.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES>
-      <root url="jar://$USER_HOME$/AppData/Local/Android/Sdk/extras/android/m2repository/com/android/support/test/espresso/espresso-core/2.2.2/espresso-core-2.2.2-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/espresso_idling_resource_2_2_2.xml b/.idea/libraries/espresso_idling_resource_2_2_2.xml
deleted file mode 100644
index df91204f..00000000
--- a/.idea/libraries/espresso_idling_resource_2_2_2.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<component name="libraryTable">
-  <library name="espresso-idling-resource-2.2.2">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.android/build-cache/0dcbbeb3c862ffabe5d9f3c1f70b25bfdf6c739e/output/jars/classes.jar!/" />
-      <root url="file://$USER_HOME$/.android/build-cache/0dcbbeb3c862ffabe5d9f3c1f70b25bfdf6c739e/output/res" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES>
-      <root url="jar://$USER_HOME$/AppData/Local/Android/Sdk/extras/android/m2repository/com/android/support/test/espresso/espresso-idling-resource/2.2.2/espresso-idling-resource-2.2.2-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/exposed_instrumentation_api_publish_0_5.xml b/.idea/libraries/exposed_instrumentation_api_publish_0_5.xml
deleted file mode 100644
index 16e1b54c..00000000
--- a/.idea/libraries/exposed_instrumentation_api_publish_0_5.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<component name="libraryTable">
-  <library name="exposed-instrumentation-api-publish-0.5">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.android/build-cache/c11e9f250159df473b4fbff8b80f455f0be2e5b5/output/jars/classes.jar!/" />
-      <root url="file://$USER_HOME$/.android/build-cache/c11e9f250159df473b4fbff8b80f455f0be2e5b5/output/res" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES>
-      <root url="jar://$USER_HOME$/AppData/Local/Android/Sdk/extras/android/m2repository/com/android/support/test/exposed-instrumentation-api-publish/0.5/exposed-instrumentation-api-publish-0.5-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/hamcrest_core_1_3.xml b/.idea/libraries/hamcrest_core_1_3.xml
deleted file mode 100644
index 157e3f34..00000000
--- a/.idea/libraries/hamcrest_core_1_3.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<component name="libraryTable">
-  <library name="hamcrest-core-1.3">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.hamcrest/hamcrest-core/1.3/42a25dc3219429f0e5d060061f71acb49bf010a0/hamcrest-core-1.3.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.hamcrest/hamcrest-core/1.3/1dc37250fbc78e23a65a67fbbaf71d2e9cbc3c0b/hamcrest-core-1.3-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/hamcrest_integration_1_3.xml b/.idea/libraries/hamcrest_integration_1_3.xml
deleted file mode 100644
index 58b2c4b3..00000000
--- a/.idea/libraries/hamcrest_integration_1_3.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="hamcrest-integration-1.3">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.hamcrest/hamcrest-integration/1.3/5de0c73fef18917cd85d0ab70bb23818685e4dfd/hamcrest-integration-1.3.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/hamcrest_library_1_3.xml b/.idea/libraries/hamcrest_library_1_3.xml
deleted file mode 100644
index 676cc632..00000000
--- a/.idea/libraries/hamcrest_library_1_3.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="hamcrest-library-1.3">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.hamcrest/hamcrest-library/1.3/4785a3c21320980282f9f33d0d1264a69040538f/hamcrest-library-1.3.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/javawriter_2_1_1.xml b/.idea/libraries/javawriter_2_1_1.xml
deleted file mode 100644
index a66fefb7..00000000
--- a/.idea/libraries/javawriter_2_1_1.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="javawriter-2.1.1">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.squareup/javawriter/2.1.1/67ff45d9ae02e583d0f9b3432a5ebbe05c30c966/javawriter-2.1.1.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/javax_annotation_api_1_2.xml b/.idea/libraries/javax_annotation_api_1_2.xml
deleted file mode 100644
index 811e73fe..00000000
--- a/.idea/libraries/javax_annotation_api_1_2.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="javax.annotation-api-1.2">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/javax.annotation/javax.annotation-api/1.2/479c1e06db31c432330183f5cae684163f186146/javax.annotation-api-1.2.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/javax_inject_1.xml b/.idea/libraries/javax_inject_1.xml
deleted file mode 100644
index 0d1d5fc9..00000000
--- a/.idea/libraries/javax_inject_1.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="javax.inject-1">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/javax.inject/javax.inject/1/6975da39a7040257bd51d21a231b76c915872d38/javax.inject-1.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/jsr305_2_0_1.xml b/.idea/libraries/jsr305_2_0_1.xml
deleted file mode 100644
index cdf98782..00000000
--- a/.idea/libraries/jsr305_2_0_1.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<component name="libraryTable">
-  <library name="jsr305-2.0.1">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.google.code.findbugs/jsr305/2.0.1/516c03b21d50a644d538de0f0369c620989cd8f0/jsr305-2.0.1.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/junit_4_12.xml b/.idea/libraries/junit_4_12.xml
deleted file mode 100644
index 305df301..00000000
--- a/.idea/libraries/junit_4_12.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<component name="libraryTable">
-  <library name="junit-4.12">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/junit/junit/4.12/2973d150c0dc1fefe998f834810d68f278ea58ec/junit-4.12.jar!/" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES>
-      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/junit/junit/4.12/a6c32b40bf3d76eca54e3c601e5d1470c86fcdfa/junit-4.12-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/rules_0_5.xml b/.idea/libraries/rules_0_5.xml
deleted file mode 100644
index 0be4378d..00000000
--- a/.idea/libraries/rules_0_5.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<component name="libraryTable">
-  <library name="rules-0.5">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.android/build-cache/8f8d46a3318b85241b55e25415619e9017c0aef1/output/jars/classes.jar!/" />
-      <root url="file://$USER_HOME$/.android/build-cache/8f8d46a3318b85241b55e25415619e9017c0aef1/output/res" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES>
-      <root url="jar://$USER_HOME$/AppData/Local/Android/Sdk/extras/android/m2repository/com/android/support/test/rules/0.5/rules-0.5-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/.idea/libraries/runner_0_5.xml b/.idea/libraries/runner_0_5.xml
deleted file mode 100644
index 0d922490..00000000
--- a/.idea/libraries/runner_0_5.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<component name="libraryTable">
-  <library name="runner-0.5">
-    <CLASSES>
-      <root url="jar://$USER_HOME$/.android/build-cache/a3a29c4e90c979d7576a0a7d8450261e0065a0a8/output/jars/classes.jar!/" />
-      <root url="file://$USER_HOME$/.android/build-cache/a3a29c4e90c979d7576a0a7d8450261e0065a0a8/output/res" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES>
-      <root url="jar://$USER_HOME$/AppData/Local/Android/Sdk/extras/android/m2repository/com/android/support/test/runner/0.5/runner-0.5-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/app/build.gradle b/app/build.gradle
index e4b338a3..aa7bfc2e 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'witness'
 
 android {
     compileSdkVersion 25
@@ -35,11 +36,6 @@ android {
 }
 
 dependencies {
-    compile fileTree(include: ['*.jar'], dir: 'libs')
-    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    })
-
     compile 'com.android.support:appcompat-v7:25.3.1'
     compile 'com.android.support:design:25.3.1'
     compile 'com.android.support.constraint:constraint-layout:1.0.2'
@@ -47,5 +43,29 @@ dependencies {
     compile 'com.android.support:recyclerview-v7:25.3.1'
     compile 'com.android.support:cardview-v7:25.3.1'
     compile 'me.dm7.barcodescanner:zxing:1.9.8'
-    testCompile 'junit:junit:4.12'
 }
+
+dependencyVerification {
+    verify = [
+            'com.android.support:design:a3e83064fe99d0a4369f9b46d8bfbe77d0c3022fffdee4be3ac3857b87cc89e3',
+            'com.android.support:appcompat-v7:ac1ebbc46589195dda3e0b1becfe410bafd75bdf3edd1cd9acf04850f3895830',
+            'com.android.support.constraint:constraint-layout:b0c688cc2b7172608f8153a689d746da40f71e52d7e2fe2bfd9df2f92db77085',
+            'com.android.support:transition:36c688825a8c0e6e879e18886de83dc90673322822d5b606ee302f70fb558e16',
+            'me.dm7.barcodescanner:zxing:d43973c9527c23fa8e6d338c6a2c458e373ce1ac6bcaa3bc41d11ae49116000d',
+            'me.dm7.barcodescanner:core:a5c8a704089b58029db166172ed8e55d756877d010a85a0b1c94fdc96ffb8f9a',
+            'com.android.support:support-v4:07d389154bcf73b47e514964df1578136b26cba78257b8a577a3ccb54beff0ae',
+            'com.android.support:recyclerview-v7:375974a8724e359d97d77fa8522c614f813a3ac4583c1807f154a3f9a054b0a1',
+            'com.android.support:cardview-v7:defc17032ffa600a82e1c7d96bb574aa5ed64e2b57e28414a245da7d6db0c666',
+            'com.android.support:animated-vector-drawable:4bc46edf1946b32d518b41416d1734e915e0cbb28021de3b340527419b070691',
+            'com.android.support:support-vector-drawable:13728f337f36d1c02d52198a6c20724edb447a0875454d829f95cb9eb4aa293b',
+            'com.android.support:support-fragment:541d6393c1e024453aca2a14f31bea0c7270ff4e2a02783f3528aa426367444d',
+            'com.android.support:support-media-compat:cbed07d07e0e84fdb4b75712f5fd946229a8af155933c9a92e41db64d00791e0',
+            'com.android.support:support-core-utils:32fac02eb2c20a77fa3e3bc3ede62392a19613f72b8f8e10f5dfa84bb4c89ea1',
+            'com.android.support:support-core-ui:6182278a6653e6c111c888963626cbb16f2d0022571cb239760475119e0b92a8',
+            'com.android.support:support-compat:e02d781268dc60aab6638d8dc20156ea11ca20b962d294b85e6f1e8418cabfa7',
+            'com.android.support:support-annotations:aedf76962584adfaed2bd3fcaa22406461c4310237fc27e301128edaa2dba2fa',
+            'com.android.support.constraint:constraint-layout-solver:8c62525a9bc5cff5633a96cb9b32fffeccaf41b8841aa87fc22607070dea9b8d',
+            'com.google.zxing:core:bba7724e02a997cec38213af77133ee8e24b0d5cf5fa7ecbc16a4fa93f11ee0d',
+    ]
+}
+
diff --git a/build.gradle b/build.gradle
index 24e27038..212a0839 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,6 +6,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath files('external-libs/gradle-witness.jar')
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }
diff --git a/external-libs/gradle-witness.jar b/external-libs/gradle-witness.jar
new file mode 100644
index 00000000..a82cb01f
Binary files /dev/null and b/external-libs/gradle-witness.jar differ